POS1515 PREVALENCE AND CLINICAL FEATURES OF LATE AND VERY LATE ONSET SYSTEMIC LUPUS ERYTHEMATOSUS
Authors: I. A. Gennaio, M. Zen, E. Fuzzi, M. Gatto, M. Larosa, L. Iaccarino, A. Doria
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Whether late-onset (LO) SLE is associated with a different, more benign disease course and better prognosis than early-onset SLE is still contradictory.[1-3] <h3>Objectives</h3> To describe the prevalence and clinical features of LO-SLE and very late onset (VLO) SLE and to compare their outcomes with those of non-LO SLE. <h3>Methods</h3> We performed a retrospective study using prospectively collected data from our cohort involving 516 patients with SLE (ACR criteria) followed between 2008 and 2022. Patients older than 50 or older than 60 years at SLE onset were defined as LO-SLE and VLO-SLE, respectively. Demographic data, and clinical and treatment history were retrieved from clinical charts. SLEDAI-2K, daily prednisone dose, SLICC Damage Index (SDI), and low disease activity (according to LLDAS definition) <sup>[1]</sup> at last follow-up in 2022 were assessed. Early mortality, within 10 years after diagnosis, was assessed in patients diagnosed in the last 15 years. <h3>Results</h3> Among 516 SLE patients regularly followed, 38 (7.4%) were LO-SLE: mean±SD age at diagnosis 56.5 ±5.7 years (range 50-72), females 78%. Of them, 10 (2% of the overall cohort) were VLO-SLE: mean±SD age at diagnosis 65 ±4.0 years (range 60-72), females 60%. Compared to early-SLE patients, LO-SLE patients had more frequently skin involvement and positive antiSSA/SSB antibodies (Table 1). Compared to non-LO-SLE, no difference in life-threatening manifestations was observed, including renal and neuropsychiatric involvement. The same trend was found in VLO-SLE. Accordingly, the use of immunosuppressants (including types of drugs) and biologics was similar (Table 1). At last follow-up, SLEDAI-2K was lower in LO-SLE patients (1±2 vs. 2±3, p=0.01), whereas the proportion of patients on glucocorticoids (21% vs 37%) and in LLDAS (84% vs 74%) was similar to that observed in non-LO-SLE. Despite that, SDI was higher in LO-SLE (2, range 0-8) than in non-LO-SLE patients (1, range 0-10, p=0.004) but after excluding items possibly related to aging (cataract, osteoporosis, low GFR, malignancy) the difference was not significant anymore. Among 165 patients diagnosed in the last 15 years, mortality was similar in LO and early-onset SLE, although deaths within 10 years after diagnosis (2 cases) all occurred in early-SLE patients. <h3>Conclusion</h3> According to our data, LO- and VLO-SLE are uncommon and seem not to be associated with more benign disease outcomes. Since life-threatening manifestations can occur in LO-SLE, these patients deserve regular follow-up. <h3>References</h3> [1] Arnaud L, et al. Late-onset systemic lupus erythematosus: epidemiology, diagnosis and treatment1 Drug Aging 2012;29(3):181-189. [2] Lin H et al. Survival analysis of late-onset systemic lupus erythematosus: a cohort study in China. Clin Rheumatol 2012;31(12):1683-9. [3] Riveros Frutos A et al. Late-onset versus early-onset systemic lupus: characteristics and outcome in a national multicentre register (RELESSER) Rheumatology 2021 6;60(4):1793-1803. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Ilenia Anna Gennaio: None declared, Margherita Zen Speakers bureau: GSK, AstraZeneca, Enrico Fuzzi: None declared, Mariele Gatto Speakers bureau: GSK, AstraZeneca, Maddalena Larosa: None declared, Luca Iaccarino Speakers bureau: GSK, AstraZeneca, Andrea Doria Consultant of: GSK, AstraZeneca.